The present invention relates to a fuel supply control system for an engine for motor vehicles.
A system in which the amount of fuel supplied to an engine is calculated based on amount of induced air, speed of engine, and other factors is known.
On the other hand, when the engine speed exceeds a predetermined value, intake and exhaust valves of the engine begin to bounce, which will cause misfiring and/or breakdown of the engine. in order to prevent such disadvantages, a fuel control system has a fuel cutoff system which operates when the engine speed exceeds a predetermined value which is slightly lower than the bounce beginning speed. However, in an automotive engine having a valve system provided with a hydraulic lash adjuster, the bounce beginning speed varies in accordance with the amount of lubricating oil. Especially, when the amount of oil in an oil pan is reduced, bubbles caused by blowing gas enter into the oil for lubricating the valve system, which will cause malfunction of the valve system and lowers the bounce beginning speed.
Namely, in the conventional system, when the amount of oil reduces, the bouncing occurs before the fuel is cut off. In other words, the conventional system cannot prevent the bouncing when the amount of oil reduces.